Symptoms and Signs of Heat Stroke (Sunstroke)

Medical Author:
Medically Reviewed on 7/25/2021

Doctor's Notes on Heat Stroke (Sunstroke)

Heat stroke is a serious emergency medical condition where the body's core temperature rises above 104 F or 40 C in adults, and 105 F or 40.5 C in children after being exposed to high temperatures in the environment. It is accompanied by neurologic symptoms and is caused by a failure of failure of the body's cooling mechanisms (such as sweating) when exposed to high heat.

Heat cramps and heat exhaustion usually occur before the onset of heat stroke. Symptoms of heat cramps and heat exhaustion include muscle cramps followed by exhaustion and profuse sweating. As these conditions progress, symptoms include

  • rapid pulse,
  • rapid breathing,
  • dizziness, and
  • headache.
  • Once the body temperature reaches 104 F or 40 C or 105 F and 40.5 C in children, heat stroke occurs and the body stops sweating,
  • the skin is hot and dry and sometimes reddish colored.

Stroke-like symptoms including

  •  confusion,
  • hallucinations,
  • seizures,
  • loss of consciousness,
  • organ damage,
  • coma, and
  • death can occur in heat stroke if not treated promptly.

Heat stroke is a medical emergency. If there are signs or symptoms of heat stroke, call 911 or get the person to a hospital’s emergency department immediately.

What is the treatment for heat stroke?

Heat stroke is a medical emergency that requires urgent medical care. If you suspect that someone has heat stroke, move them to a cool environment and try to cool the body by removing clothes or misting with water while you summon emergency care.

Medical professionals treating heat stroke will try aggressive measures to cool the body including immersion in cold water, ice packs, cooling blankets, and evaporation cooling methods. Medications may be given to reduce shivering during this process.

Other treatments may include support for breathing and circulation as needed.

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.